feat: Adds some documenation comments

Sources/SharedModels/Vendor.swift

@@ -1,6 +1,10 @@
 import Dependencies
 import Foundation
 
+/// Represents a vendor item in the database.
+///
+/// A vendor is parent item that contains one or more branches where purchase orders
+/// can be issued to.  It is primarily a name space to group related branches together.
 public struct Vendor: Codable, Equatable, Identifiable, Sendable {
   public var id: UUID
   public var name: String
@@ -25,6 +29,7 @@ public struct Vendor: Codable, Equatable, Identifiable, Sendable {
 
 public extension Vendor {
 
+  /// Represents the fields required to generate a new vendor in the database.
   struct Create: Codable, Sendable, Equatable {
     public let name: String
 
@@ -33,6 +38,7 @@ public extension Vendor {
     }
   }
 
+  /// Represents the fields required to update a vendor in the database.
   struct Update: Codable, Sendable, Equatable {
     public let name: String